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` A. W, MELLOWES May 30, 1933. MECHANICAL REFRIGERATING EvAPoRATon Original Filed Feb. 28, 1921 I e C u l E Reissued May 30, 1933 `UNITED STATES PATENT' OFFICE ALFRED W. MELLOWES, 0F MILWAUKEE,- WISOONBIN, ASSIGNOB 0F ONE-millo EDWIN B.- H. TOWER, JB., 0F MILWAUKEE, WISGONSIN MECHANICAL REFBIGEBATING EVAPOBATOB fOriginaI application led February 28, 1921, Serial No. 448,412, Intent No. 1,833,846, dated November 84, 1931. Divided and application led November 23, 1931, Serial No. 576.805, Patent No. 1,847,057, dated February 28, 1932. Application for reissue led Hatch 3, 1933. lerial No. 660,541.

The invention relates to a mechanical refrigci'ating evaporator. l

The present application is for a reissue of Letters .Patent No. 1,847,057, February 23, 19321 issued on a division of application Serial No. 448,412, filed February 28, 1921, now Letters Patent No. 1,833,846, issued November 24, 1931.

The mechanical lefrigerating evaporator to which the invention applies in particular is of the type which has liquid refrigerant delivered thereto from a condenser and vaporized refrigerant returned therefrom to a compressor. e

The liquid refrigerant which is delivered to the evaporator from the compressor has oil coinmingled therewith.

- The invention has as an object to provide a mechanical refrigerating evaporator with an oil separator in which oil is separated from liquid refrigerant by flotation to the surface thereof and then drawn from the separating reservoir with vaporized refrigerant and returned therewith to the compressor.

Another object is to provide a mechanical refrigerating evaporator with' an 011 separating reservoir which will accumulate va porized refrigerant above the liquid refrigerant and keep liquid refrigerant from being returned to the compressor.

Another object is to provide a mechanical refrigerating evaporator with an oil separating reservoir from which only oil and va. porized refrigerant will be -drawn and returned to the compressor.

Another object isto provide a mechanical refrigcrating evaporator with an oil separating reservoirfin which the liquid refrigerant will be kept from rising above a given level therein.

According to this invention as it is embodied in practice, the evaporator is provided with a liquid refrigerant container to absorb heat by vaporization of liquid refrigerant therein and an oil separating reservoir arranged above the liquid refrigerant container in communication therewith to accumulate vaporized refrigerant'therefrom and to contain liquid refrigerant'and allow the oil commingled therewith to separate therefrom by flotation to the surface thereof and having the liquid refrigerant therein limited in quantit7 to keep it from rising above a. given leve The separating reservoir is provided with a discharge pipe or other means arranged to draw therefrom and return to the compressor the separated oil and vaporized refrigerant and to keep liquid refrigerant from being drawn from the separating reservoir with the separated oil and vaporized refri erant.

The separating reservoir is ordinari y provided with means arranged as a part thereof to limit in quantity the liquid refrigerant therein to keep it from rising above a given level. 4 l

The evaporator which is illustrated in the accompanying drawing exemplifies the invention and the views thereof are as follows:

Fig. 1 is a front sectional elevation;

Fig. 2 is a side elevation in section on the line 2 2, Fig. 1; and

Fig. 3 is an enlarged front sectional elevation of the oil separator.

The oil separator is shown and described as applied to an evaporator of the type described and claimed in the aforesaid Letters Patent No. 1,833,946, issued November 24,

1931, but that particular evaporator with the.

oil separator combined therewith is not claimed, herein.

The evaporator is provided with a liquid refrigerant container which is formed in general by multiple refrigerant ducts or tubes 1 which are arranged in two opposite groups.

The refrigerant tubes are connected at the lower end in' multiple to a refrigerant supply header manifold 2 and at the upper end in multiple to a refrigerant discharge header or manifold 3.

.The refrigerant discharge manifold is constructed to provide an oil separator in which oil commingled with liquid refrigerant is separated therefrom and then returned to the compressor with vaporized refrigerant.

The multiple refrigerant tubes are ararranged to provide at the lower part thereof multiple freezing ducts or tubes 4 upon both lateral sides of a freezing space and at the upper part thereof multiple cooling ducts or tubes 5 in direct contact with the ambient air in a cooling space within a cooling or refrigerating compartment.

The freezing space has arranged therein a freezing compartment 6 which has two chambers, each of which is open at its front end to receive endwisc a removable icetray 7.

The freezing tubes and freezing compartment are enclosed Within a tank 8 which contains -brine or other suitable liquid to increase the thermal conductivity between the freezing tubes and freezing compartment, but other expedients may be employed to attain the same end.

The freezing compartment is carried by `the tank, and the tank has its top attached to the refrigerant tubes, but other ways may be employed to support the freezing compartment within the freezing space.

The air cooling tubes are reiexedy above the freezing compartment to increase the heat absorbing surface thereof within a given space.

The refrigerant tubes may be increased in number and the shape thereof varied to obtain sufficient heat absorbing surface within given over-all dimensions.

The refrigerant supply manifold has connected thereto a refrigerant delivery conduit or pipe 9 through which liquid refrigerant is delivered thereto from a condenser.

The refrigerant discharge manifold has connected thereto a refrigerant discharge conduit or pipe 10 throughwhich vaporized refrigerant is returned to a compressor.

The evaporator isl employed in a refrigerator in which it is arranged to'c'ool the air in a cooling or refrigerating compartment.

The refrigerating apparatus with which the refrigerator is provided and of which the evaporator is a part has a condenser to supply or deliver liquid refrigerant to the evaporator and a compressor to withdraw vaporized refriglerant from the evaporator by suction and t en compress this vaporized refrigerant and deliver 1t to the condenser to be liquefied therein.

The evaporator has the liquid refrigerant which is supplied or delivered thereto by the condenser regulated or controlled to keep the refrigerant tubes filled with li uid refrigerant to a suilicient extent to ma e sufficient liquid refrigerant always resent and available in both the freezing tu es and the cooling tubes to absorb sufficient heat to freeze the water in the freezing compartment and cool the air in the cooling compartment at a rapidrate.

The-freezing tubes will create a, freezing temperature about twenty degrees Fahrenheit 20 F.) in the freezing compartment and t e cooling tubes will create a cooling temperature about forty degrees Fahrenheit (40 F.) in the cooling compartment under variations in conditions causmg a wide variation in the heat required to be absorbed from Y thecoolingv compartment and the freezing' com artment.

T e variations in the conditions causing a wide variation-in the heat required to bc absorbed by the eva orator from the cooling compartment an the freezing compartment are variations in the temperature outside the refrigerator, variations in the temperature and quantity of food placed in the cooling compartment, variations in the temperature and quantity of water placed in the freezing compartment, and variations in the time outside airis admitted to the refrigerator upon its door beingopened to obtain access to the insidethereof.

The oil separator with which the evaporator is provided to separate oil from liquid refrigerant and return it to the compressor has a separating receiver or reservoir 11 baving a depending trough 12, and the refrigerant tubes extend into the separating reservoir and communicate therewith at the upper part thereof.

The separating reservoir absorbs heat from the air in thecooling compartment in addition to that absorbed by the cooling tubes as it receives and contains liquid refri erant and the upper warm air in the coo 'ng compartment passes in part over its outside surface in direct contact therewith.

The separating reservoir has extending upward therein through the trough a refrigerant dischargepipe 10 commumcatin therewith below the refrigerant tubes an formin a combined oil overiiow and vaporized re gerant outlet 13 to dischargeoil by gravity and va orized refrigerant by suction.

The trough epending from the separating reservoir is connected to a refrigerant tube by an ascending back-ow'pipe or conduit 14 communicating with the troughat thelower part thereof and the refrigerant tube below the over-flow outlet from the separating reservoir.

When the liquid refrigerant in the refrigy pipe and returns with vaporized refrigerant to the compressor.

The separating reservoir, instead of having the oil drawn or discharged therefrom by overflowing into a discharge pipe under the action of avity,`may have the oil drawn or dischargeTtherefrom'in other ways and by other means.

lll

If the liquid refrigerant in the refrigerant tubes is below the back-flow pipe, the liquid refrigerant in the separating reservoir will be kept from rising to the over-flow outlet by returning to the refrigerant tubes through l the back-flow pipe.

The back-flow pipe is restricted in size to keep sufficient liquid refrigerant in the separating reservoir to enable the oil separated therefrom to rise to the over-flow outlet.

If the refrigerant tubes are filled with liquid refrigerant to above the back-flow pipe, then the liquid refrigerant in the separating reservoir cannot be returned by the back-flow pipe to the refrigerant tubes, but the liquid refrigerant may be kept from rising to the oil over-flow outlet in other ways, as by regulating and controlling the liquid refrigerant supplied or delivered to the refrigerant tubes from the condenser.

The oil separator set forth herein may be applied to different evaporators and various modifications may be made therein without departing from the invention as hereinafter' claimed.

The invention set forth in the foregoing specification is hereby claimed as follows:

i separated by flotation from liquid refrig- 1. A mechanical refrigerating evaporator, comprising a refrigerant container having liquefied refrigerant delivered thereto and vaporized refrigerant discharged therefrom,

an oil separating reservoir arranged above said refrigerant container in communication therewith to contain liquid refrigerant and oil commingled therewith and receive oil from said refrigerant container and provided with an over-How outlet arranged above the liquid refrigerant and below the vaporized refrigerant therein to discharge by gravity oil separated by otation from the liquid refrigerant in said reservoir, and means to keep the liquid refrigerant in said reservoir. from rising to said over-flow outlet.

2. A mechanical refrigerating evaporator,

. comprising an oil separ'ating reservoir having an over-flow outlet arranged above the liquid refrigerant and below the vaporized refrigerant therein to discharge therefrom by gravity with vaporized refrigerant oil erant in said'reservoir, a refrigerant container depending lfrom said reservoir and communicating therewith, means to deliver liquid refrigerant to saidrefrigerant container, and means to keep the liquid refrigerant in said reservoir from rising to said overflow outlet.

3. A mechanical refrigeratingevaporator, comprising a tubular liquid refrigerant container, an oil separating reservoir arranged at the top of said refrigerant container to separate oil from liquid refrigerant by flotation and having an over-How outlet arranged above the liquid refrigerant .and'below the vaporized refrigerant therein to discharge by gravity with vaporized refrigerant oil Heating upon the liquid refrigerant in said separating reservoir, and means to keep the liquid refrigerant in said separating reservoir from rising to said over-flow outlet.

4. A mechanical refrigerating evaporator,

Vcomprising a refrigerant container having liquid refrigerant delivered thereto from a condenser and vaporized refrigerant withdrawn therefrom and returned to a compressor, a separating reservoir arranged at ther liquid refrigerant in said reservoir from rising to said over-flow outlet.

5. A mechanical refrigerating evaporator, comprising the combination with a liquid refrigerant container having liquid'refrigerant delivered thereto and vaporized refrigerant discharged therefrom, of a separating i'eservoir arranged at the top of said container in communication therewith to receive vaporized refrigerant-from said liquid refrigerant container and contain liquid refrigerant with oil commingled therewith and having an oil over-flow outlet arranged above the liquid refrigerant and below the vaporized refrigerant therein in a position to discharge therefrom by gravity oil separated by flotation from liquid refrigerant in said reservoir and over-iiowing into said over-flow out et.

6. A mechanical refrigerating evaporator,

comprising the combination with al liquid,

99. iff:

frigerant with oil commingled therewith and having a vaporized refrigerant outlet and an oil over-How outlet arranged above the liquid refrigerant and below the vaporized refrigerant therein in a position to discharge therefrom by gravity oil separated by flotation from liquid refrigerant in said reservoir and over-flowing into said over-flow outlet, and a discharge pipe connected to said oil over-flow outlet and vaporized refrigerant outlet to return separated oil and vaporized refrigerant from said reservoir to a compressor.

7. A mechanic-al refrigeratingevaporator, comprising the combination with a liquid refrigerant container having liquid refrigeri .tainer-in/communication therewith to receive vaporized refrigerant from said liquid refrigerant container' and contain liqu1d refrigerant with oil commingled therewith and having a vaporized refrigerant outlet and an oil over-flow outlet arranged above the liquid refrigerant and below the vaporized refrigerant therein in a position to discharge therefrom by gravity oil separated by flotation from liquid refrigerant in said reservoir and over-flowing into said oil over-flow outlet, means to limit in quantity the vaporized refrigerant in said reservoir to keep it from rising to said oil'over-ilow outlet, and a discharge pipe connected to said oil over-flow outlet and vaporized refrigerant outlet to return separated oil and vaporized refrigerant from said reservoir to a compressor.

8. A mechanical refrigerating evaporator,

comprising a refrigerant container supplied with liquid refrigerant, a separating reservoir connected to said container at the top thereof to receive vaporized refrigerant and contain oil separated by flotation from liquid refrigerant therein and having an over-flow outlet arranged above the liquid refrigerant therein in a position to allow the separated oil to over-flow therethrough by gravity, and a discharge pipe connected to said reservoir to withdraw vaporized refrigerant therefrom and return therewith to a compressor separated oil over-flowing through said over-flow outlet.

9. A mechanical refrigerating evaporator, comprising the combination with a refrigerant container provided with multiple refrigerant duets, of a separating reservoir arranged at the top of said container in communication therewith to receive vaporized refrigerant from said liquid refrigerant container and contain liquid refrigerant with oil commingled therewith and havinga vapor-.

ized refrigerant outlet and an oil over-flow outlet arranged abovethe liquid refrigerant and below the vaporized refrigerant therein ,in a position to discharge therefrom by' gravity oil separated by flotation from liquid refrigerant in said reservoir and over-flowingthrough said over-flow outlet.

10. A mechanical refrigerating evaporator, comprising the combination with a refrigerant container provided with multiple refrigerant ducts, of a separating reservoir arranged at the top o f said containerin communication therewith to receive vaporized refrigerant from said liquid refrigerant container and contain liquid refrigerant with oil` commingled therewith and having a vaporized refrigerant outletl and an oil overflow outlet arranged above the liquid refrigerant and below the vaporized nefrigerant arated oil and vaporized refrigerant fromv said reservoir to acompressor.

11. A mechanical refrigerating evaporator, comprising an oil separating reservoir to accumulate the vaporized refrigerant from s liquid refrigerant in the evaporator and to contain liquid refrigerant and allow the oil commingled therewith to separate therefrom by flotation to the top thereof, a liquid refrigerant container arranged below said separating reservoir to contain liquid refrigerant and absorb heat by vaporization thereof and having multiple tubes communicating at the top thereof with said'separating reservoir,` and means arranged to draw from said separating reservoir separated oil and vaporized refrigerant and to keep liquid refrigerant from being drawn drom said separating reservoir with the separated oil and vaporized refrigerant.

12. A mechanical refrigerating evaporator, comprising an oil separating reservoir to accumulate the vaporized refrigerant from liquid refrigerant in the evaporator and to contain liquid refrigerant and allow the oil Vcommingled therewith to separate therefrom by flotation to the top thereof, a liquid refrigerant container arranged below said separating reservoir to contain liquid refrigerant and absorb heat by vaporization thereof and having multiple tubes communicating at the top thereof with said separating reservoid, means arranged as a part of said separating reservoir to limit in quantity the liquid refrigerant in said separating reser- 'voir to keep it from rising above a given level therein, and means arranged to draw from said separatingreservoir the separated oil and vaporized refrigerant therein and to keep liquid refrigerant from being drawn from said separating reservoir with the separated oil and vaporized refrigerant.

13. A mechanical refrigerating evaporaV tor, comprising .the combination with a refrigerant container to absorb heat by vaporization of liquid refrigerant therein, of an oil separating reservoir arranged above said refrigerant container in communication therewith to accumulate the vaporized refrigerant therefrom and to contain liquid refrigerant and allow the oil commingled therewith to separate therefrom by flotation to the top thereof and having the liquid refrigerant therein limited in quantity to keep it from rising above a given level, and means arranged to draw from said separating'reserdrawn from said separating reservoir with the separated oil and vaporized refrigerant.

J4. A mechanical refrigerating evaporator, comprising the combination with a refrigerant container to absorb heat by vaporization of liquid refrigerant therein, of an oil separating reservoir arranged above said refrigerant container in communication therewith to accumulate thevaporized refrigerant therefrom and to contain liquid refrigerant and allow the oil commingled therewith to separate therefrom by iotation to the top thereof, means arranged as a part of said separating reservoir to limit in quantity the liquid refrigerant in said separating reservoir to keep it from rising above a given level therein, and means arranged 'to draw from said separating. reservoir separated oil and vaporized refrigerant and to keep liquid refrigerant from being drawn from said separating reservoir with the separated oil and vaporized refrigerant.

15. A mechanical refrigerating evaporator, comprising the combination with a refrigerant container to absorb heat by va-porization of liquid refrigerant therein, of an oilV sep- 'arating reservoir arranged above said refrlgerant container in communication therewith to accumulate the vaporized refrigerant therefrom and to containliquid refrigerant and allow the oil commingled therewith `to separate therefrom by flotation to the top thereof and having the liquid refrigerant therein limited in quantity t0 keep it from rising above a given level, and a discharge pipe arranged in communication with said separatin reservoir above the level of the liquid re igerant therein to draw therefrom separated oil and vaporized refrigerant and to keepliquid refrigerant from being drawn from said separating reservoir with the separated oil and vaporized refrigerant.

16. A mechanical refrigerating evaporator, comprising the combination with a rewith the separated oil and vaporized refrigerant.

In witness whereof, I have hereunto subscribed my name.

l ALFRED W. MELLOWES.

frigerant container to absorb heat by va oro ization of liquid refrigerant therein, o an oil separating reservoirarranged above said refrigerant container in communication therewith to accumulate the vaporized refrigerant therefrom and to contain liquid refrigerant and allow the oil vcommingled therewith to separate therefrom bv otation to the top thereof, means arrange as a part of said separatin reservoir to limit in quantity the liquid re ri rant in said separating reservoir to keep it rom rising above a given level` therein, and a discharge pipe in communication with said reservoir above the level of the liquid refrigerant therein to draw therefrom separated oil and vapor-ized refrigerant and to keep liquid refrigerant from being drawn from said separating reservoir 

